WCSXFRM(3C)WCSXFRM(3C)NAME
wcsxfrm, wsxfrm - wide character string transformation
SYNOPSIS
#include <wchar.h>
size_t wcsxfrm(wchar_t *ws1, const wchar_t *ws2, size_t n);
size_t wsxfrm(wchar_t *ws1, const wchar_t *ws2, size_t n);
DESCRIPTION
The wcsxfrm() and wcsxfrm() functions transform the wide character
string pointed to by ws2 and place the resulting wide character string
into the array pointed to by ws1. The transformation is such that if
either the wcscmp(3C) or wscmp(3C) functions are applied to two trans‐
formed wide strings, they return a value greater than, equal to, or
less than 0, corresponding to the result of the wcscoll(3C) or
wscoll(3C) function applied to the same two original wide character
strings. No more than n wide-character codes are placed into the
resulting array pointed to by ws1, including the terminating null wide-
character code. If n is 0, ws1 is permitted to be a null pointer. If
copying takes place between objects that overlap, the behavior is unde‐
fined.
The wcsxfrm() and wsxfrm() functions do not change the setting of errno
if successful.
Since no return value is reserved to indicate an error, an application
wishing to check for error situations should set errno to 0, then call
wcsxfrm() or wsxfrm(), then check errno.
RETURN VALUES
The wcsxfrm() and wsxfrm() functions return the length of the trans‐
formed wide character string (not including the terminating null wide-
character code). If the value returned is n or more, the contents of
the array pointed to by ws1 are indeterminate.
On error, wcsxfrm() and wsxfrm() may set errno but no return value is
reserved to indicate an error.
ERRORS
The wcsxfrm() and wsxfrm() functions may fail if:
EINVAL
The wide character string pointed to by ws2 contains wide-
character codes outside the domain of the collating sequence.
USAGE
The transformation function is such that two transformed wide charac‐
ter strings can be ordered by the wcscmp() or wscmp() functions as
appropriate to collating sequence information in the program's locale
(category LC_COLLATE).
The fact that when n is 0, ws1 is permitted to be a null pointer, is
useful to determine the size of the ws1 array prior to making the
transformation.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────────────┤
│CSI │ Enabled │
├────────────────────┼─────────────────────────┤
│Interface Stability │ wcsxfrm() is Standard │
├────────────────────┼─────────────────────────┤
│MT-Level │ MT-Safe with exceptions │
└────────────────────┴─────────────────────────┘
The wcsxfrm() and wsxfrm() functions can be used safely in multi‐
threaded applications as long as setlocale(3C) is not being called to
change the locale.
SEE ALSOsetlocale(3C), wcscmp(3C), wcscoll(3C), wscmp(3C), wscoll(3C),
attributes(5), standards(5)
Nov 1, 2003 WCSXFRM(3C)
